And the infection underscores the ongoing security risks in
what has become the U.S. military’s most important weapons
system.

“We keep wiping it off, and it keeps coming back,” says a
source familiar with the network infection, one of three that
told Danger Room about the virus. “We think it’s benign. But we
just don’t know.”

Network experts aren't sure if the "keylogger" virus was planted
in the weapons system or naturally migrated there from unsecure
points. Even more alarmingly, they do not know how far it has
spread.

They are certain, however, that the malware has accessed
classified data and are allowing that sensitive information could
be hijacked and transmitted over the open Internet.

Airforce spokesman Lt. Col. Tadd Sholitis declined to comment on
the virus, but told
Wired: “We generally do not discuss specific vulnerabilities,
threats, or responses to our computer networks, since that helps
people looking to exploit or attack our systems to refine their
approach. We invest a lot in protecting and monitoring our
systems to counter threats and ensure security, which includes a
comprehensive response to viruses, worms, and other malware we
discover.”

Wired's source says, "[The virus] is getting a lot of
attention, but no one is panicking. Yet."